MECHANISMS OF CYTOSKELETAL INJURY BY HEAVY METALS

接触金属的工人可能会出现严重的健康问题 工作场所的氛围。慢性或急性暴露于含汞烟雾，或 铅可导致贫血和神经损伤，而急性接触铅 镉或砷可导致肺气肿。长期暴露于AS最终可以 会导致肺癌，而长期接触镉会导致严重的 肾脏受损。目前尚不清楚这些金属的哪些细胞内靶点 对其全身毒性的表达有直接影响。这 该项目是关于以细胞骨架为目标的初步研究 这些金属对细胞内的损害。它的目的是建立一个 为未来将细胞骨骼损伤与全身性相关的研究奠定基础 毒性。所有这些金属都强烈地与巯基结合。然而，CD， 汞、铅也可与钙调蛋白结合并激活。相比之下，由于 无法激活钙调蛋白。微管含有巯基， 必须保持减少才能进行装配，并保持装配的 州政府。此外，微管动力学受钙的调节，通过 钙调素的激活。因此，镉、汞和铅可能通过以下方式影响微管 或钙调素结合，而AS的作用是 由于巯基的结合。细胞总蛋白含量的变化 而细胞骨架蛋白在金属暴露过程中的巯基 用DTNB比色法和~3H-NEM标记法监测。 钙、镉、汞和铅对钙调蛋白的激活作用将通过 钙调素抑制剂对钙离子和钙离子影响的研究 微管上的其他金属。钙调素与金属离子的结合 通过在存在的情况下增强微管蛋白组装来确定 通过钙调蛋白的螯合作用产生的钙调蛋白。最后，绑定和 钙调蛋白的激活表现为激活的运动速度较慢。 非变性PAGE中的钙调蛋白。钙调蛋白依赖的磷酸化 用SDS-PAGE和放射自显影对细胞骨架蛋白进行分析。

Serious health problems can occur in workers exposed to metals in the workplace atmosphere. Chronic or acute exposure to fumes containing Hg, or Pb can result in anemia and neurological damage, while acute exposure to Cd, or As can result in emphysema. Long term exposure to As ultimately can lead to lung cancer, while long term exposure to Cd can result in severe renal damage. It is unclear which intracellular targets of these metals have a direct effect on the expression of their systemic toxicity. This project represents initial studies concerning the cytoskeleton as a target of intracellular damage by these metals. It is intended to establish a basis for future studies relating cytoskeletal damage to systemic toxicity. All these metals bind avidly to sulfhydryl groups. However, Cd, Hg, and Pb can also bind to and activate calmodulin. In contrast, As cannot activate calmodulin. Microtubules contain sulfhydryl groups that must remain reduced for assembly to occur, and to maintain the assembled state. In addition, microtubule dynamics are regulated by calcium, via activation of calmodulin. Thus Cd, Hg, and Pb may affect microtubules by sulfhydryl binding, or calmodulin binding while the effects of As would be due to sulfhydryl binding. Changes in the amount of total cellular protein and cytoskeletal protein sulfhydryl groups during metal exposure will be monitored with the DTNB colorimetric assay and the 3H-NEM labeling assay. Activation of calmodulin by Ca, Cd, Hg, and Pb will be studied by determining the effects of calmodulin inhibitors on the effects of Ca and other metals on microtubules. Calmodulin binding of metal ions will be determined by an enhancement of tubulin assembly in the presence of calmodulin by the chelating action of calmodulin. Finally, binding and activation of calmodulin is shown by the slower mobility of activated calmodulin in non-denaturing PAGE. Calmodulin dependent phosphorylation of cytoskeletal proteins is analyzed with SDS-PAGE and autoradiography.